DIAMINE AND POLYAMINE OXIDASE ACTIVITIES IN PHYTOHEMAGGLUTININ-INDUCED GROWTH OF RAT SMALL-INTESTINE

The activities of diamine and polyamine oxidases, two enzymes of polya mine catabolism, were studied in hyperplastic growth of rat small inte stine induced by phytohaemagglutinin. This growth, evaluated by the el ongation of Lieberkuhn's crypts, was more extensive in the proximal th an in the distal parts of the gut. The activity of diamine oxidase was significantly reduced in the proximal (70%), medial (45%) and the dis tal (25%) parts. The activity of polyamine oxidase was doubled. The co ncentrations of putrescine, cadaverine and spermidine were significant ly elevated in the three intestinal parts studied, whereas those of hi stamine and spermine were unchanged. It appears that changes in the ac tivities of diamine and polyamine oxidases may contribute to the incre ased putrescine content, which is necessary to maintain active polyami ne turnover for sustaining growth of the gut.